Multivariable prediction models for long-term outcomes after hip fracture: A protocol for a systematic review

Background: Hip fracture results in high mortality and, for many survivors, long-term functional limitations. Multivariable prediction models for hip fracture outcomes have the potential to aid clinical-decision making as well as risk-adjustment in national audits of care. The aim of this study is to identify, critically appraise and synthesise published multivariable prediction models for long-term outcomes after hip fracture. Protocol: The systematic review will include a literature search of electronic databases (MEDLINE, Embase, Scopus, Web of Science and CINAHL) for journal articles. Search terms related to hip fracture, prognosis and outcomes will be included. Study selection criteria includes studies of people with hip fracture where the study aimed to predict one or more long-term outcomes through derivation or validation of a multivariable prediction model. Studies will be excluded if they focus only on the predictive value of individual factors, or only include patients with periprosthetic fractures, fractures managed non-surgically or younger patients. Covidence software will be used for data management. Two review authors will independently conduct study selection, data extraction and appraisal. Data will be extracted based on the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS) checklist. Risk of bias assessment will be conducted using the Prediction model Risk of Bias Assessment Tool (PROBAST). Characteristics and results of all studies will be narratively synthesised and presented in tables. Where the same model has been validated in multiple studies, a meta-analysis of discrimination and calibration will be conducted. Conclusions: This systematic review will aim to identify multivariable models for hip fracture outcome prognosis that have been derived using high quality methods. Results will highlight if current models have the potential for further assessment for use in both clinical decision making and improving methods of national hip fracture audits. PROSPERO registration: CRD42022330019 (25th May 2022).